Project Summary/Abstract This application requests support for a scientific workshop under PA-16-294 focusing on the lessons learned from the seminal 2012 and 2016 Lancet Physical Activity Series. In this two-day workshop ?Learning from The Lancet: Lessons and future research directions drawn from the 2012 and 2016 global series on physical activity and health?, we will convene the series lead authors, physical activity and cancer prevention researchers and policy experts from universities, government, non-governmental organizations (NGOs), and multi-lateral organizations in order to develop research and public health practice agendas for physical activity and cancer prevention. Physical inactivity is an underlying cause of 13 site-specific cancers1. More than 10% of the mortality from breast and colon cancer is attributable to physical inactivity2. Thus, better understanding how to increase physical activity is extremely important for global cancer prevention and control. Four of the papers from the 2012 Lancet series have already reached 1000 citations and two of the papers from the 2016 series have been identified among the most important publications of 20162-6. As a whole, the two series constitute a state-of-the-art summary of global knowledge of physical activity and health, and can provide a road map for future research and policy initiatives. Leadership for this event will be provided by the Moores Cancer Center (MCC) and the Institute for Public Health (IPH) at UC San Diego with partners including Active Living Research (ALR), the Global Observatory for Physical Activity7-9, the International Society for Physical Activity and Health10, The Lancet, American College of Sports Medicine (ACSM) and the Robert Wood Johnson Foundation. While there have been many workshops and conferences focused on physical activity and health, this workshop will uniquely draw upon the syntheses of global knowledge from the Lancet series. This will allow us to build upon the extensive work done to develop the papers in each topic area and then focus on research gaps and policy recommendations related to physical activity and cancer prevention. We will have a special emphasis on disabled and underserved populations as these groups stand to benefit substantially from physically activity, but have been less well studied. The Specific Aims are to: convene a two-day scientific workshop that will engage 40 academic researchers and policy experts representing multiple fields and sectors to draft a research agenda for global physical activity and cancer prevention; synthesize the key lessons from the 10 papers that constituted the two series; identify and summarize important research and translation gaps; prioritize the most actionable research and translation issues for physical activity promotion; disseminate the workshop results via two published articles (one focused on research gaps and one on policy recommendations), presentations, social media, and research and policy briefs to be distributed by our partners; and evaluate the workshop to assess how well the objectives were met.